The objective of the proposed research is to examine the efficacy of several psychological assessment procedures in measuring drug use and abuse among Hispanics. The specific aims are: (1) to assess the reliability and validity of the Diagnostic Interview Schedule (DIS) when used in English and Spanish with Hispanics and in English with Anglos; (2) to assess whether the phenomenology of selected disorders (e.g., drug abuse, alcohol abuse, antisocial personality disorder, anxiety, depression) varies by attributes such as language (English/Spanish), ethnic status (Anglo/Hispanic), and acculturation; and (3) to assess the reliability, validity, and utility of two brief screening instruments relevant to studies of substance abuse, the HHANES/NIDA questionnaire on drug use and the Center for Epidemiologic Studies Depression Scale (CES-D), when used in English and Spanish with Hispanics and in English with Anglos. Study subjects will consist of a sample of 192 patients participating in a drug abuse treatment program, a comparison group of 160 patients participating in an alcohol abuse treatment program and a second comparison group of 247 patients in treatment for general (nondrug, nonalcohol) psychiatric dysfunction. The design involves assessing Anglos, monolingual English-speaking Hispanics, monolingual Spanish-speaking Hispanics and bilingual Hispanics. This latter group was randomly assigned to English and Spanish interviews. The DIS will assessed for test-retest reliability, concordance (i.e., sensitivity/specificity) between the DIS, the hospital/clinic chart diagnosis, and a diagnosis made using the DSM III Checklist by a research team clinician blind to the other two diagnostic outcomes. Concordance between this latter diagnosis and the medical record diagnosis also will be examined. Differential manifestation of drug use/abuse will be examined using multivariate classification procedures (cluster analysis, confirmatory factor analysis, latent trait analysis) to analyze symptom patterns within diagnostic groups and across diagnostic groups as a function of ethnic status, language and acculturation. The screening instruments (CES-D and HHANES/NIDA) will be assessed using item nonresponse, test-retest and internal coinsistency reliability and also sensitivity/specififity using as the criteria DSM III diagnoses of drug abuse from the three clinical sources: the lay-administered DIS, hospital/clinic medical record, and research staff clinician using the Checklist.